Fixing protoype spawning

evennia/commands/default/building.py

@@ -13,13 +13,12 @@ from evennia.utils.utils import (
     class_from_module,
     get_all_typeclasses,
     variable_from_module,
-    dbref,
+    dbref, interactive
 )
 from evennia.utils.eveditor import EvEditor
 from evennia.utils.evmore import EvMore
 from evennia.prototypes import spawner, prototypes as protlib, menus as olc_menus
 from evennia.utils.ansi import raw
-from evennia.prototypes.menus import _format_diff_text_and_options
 
 COMMAND_DEFAULT_CLASS = class_from_module(settings.COMMAND_DEFAULT_CLASS)
 
@@ -2099,10 +2098,10 @@ class CmdTypeclass(COMMAND_DEFAULT_CLASS):
             # to confirm changes.
             if "prototype" in self.switches:
                 diff, _ = spawner.prototype_diff_from_object(prototype, obj)
-                txt, options = _format_diff_text_and_options(diff, objects=[obj])
+                txt = spawner.format_diff(diff)
                 prompt = (
                     "Applying prototype '%s' over '%s' will cause the follow changes:\n%s\n"
-                    % (prototype["key"], obj.name, "\n".join(txt))
+                    % (prototype["key"], obj.name, txt)
                 )
                 if not reset:
                     prompt += "\n|yWARNING:|n Use the /reset switch to apply the prototype over a blank state."
@@ -3227,6 +3226,10 @@ class CmdTag(COMMAND_DEFAULT_CLASS):
             self.caller.msg(string)
 
 
+# helper functions for spawn
+
+
+
 class CmdSpawn(COMMAND_DEFAULT_CLASS):
     """
     spawn objects from prototype
@@ -3256,7 +3259,7 @@ class CmdSpawn(COMMAND_DEFAULT_CLASS):
                them with latest version of given prototype. If given with /save,
                will auto-update all objects with the old version of the prototype
                without asking first.
-      edit, olc - create/manipulate prototype in a menu interface.
+      edit, menu, olc - create/manipulate prototype in a menu interface.
 
     Example:
       spawn GOBLIN
@@ -3309,56 +3312,203 @@ class CmdSpawn(COMMAND_DEFAULT_CLASS):
     locks = "cmd:perm(spawn) or perm(Builder)"
     help_category = "Building"
 
+    def _search_prototype(self, prototype_key, quiet=False):
+        """
+        Search for prototype and handle no/multi-match and access.
+
+        Returns a single found prototype or None - in the
+        case, the caller has already been informed of the
+        search error we need not do any further action.
+
+        """
+        prototypes = protlib.search_prototype(prototype_key)
+        nprots = len(prototypes)
+
+        # handle the search result
+        err = None
+        if not prototypes:
+            err = f"No prototype named '{prototype_key}'."
+        elif nprots > 1:
+            err = "Found {} prototypes matching '{}':\n  {}".format(
+                    nprots,
+                    prototype_key,
+                    ", ".join(proto.get("prototype_key", "") for proto in prototypes),
+                    )
+        else:
+            # we have a single prototype, check access
+            prototype = prototypes[0]
+            if not self.caller.locks.check_lockstring(
+                    self.caller, prototype.get("prototype_locks", ""),
+                    access_type="spawn", default=True):
+                err = "You don't have access to use this prototype."
+
+        if err:
+            # return None on any error
+            if not quiet:
+                self.caller.msg(err)
+            return
+        return prototype
+
+    def _parse_prototype(self, inp, expect=dict):
+        """
+        Parse a prototype dict or key from the input and convert it safely
+        into a dict if appropriate.
+
+        Args:
+            inp (str): The input from user.
+            expect (type, optional):
+        Returns:
+            prototype (dict, str or None): The parsed prototype. If None, the error
+                was already reported.
+
+        """
+        eval_err = None
+        try:
+            prototype = _LITERAL_EVAL(inp)
+        except (SyntaxError, ValueError) as err:
+            # treat as string
+            eval_err = err
+            prototype = utils.to_str(inp)
+        finally:
+            # it's possible that the input was a prototype-key, in which case
+            # it's okay for the LITERAL_EVAL to fail. Only if the result does not
+            # match the expected type do we have a problem.
+            if not isinstance(prototype, expect):
+                if eval_err:
+                    string = (
+                        f"{inp}\n{eval_err}\n|RCritical Python syntax error in argument. Only primitive "
+                        "Python structures are allowed. \nMake sure to use correct "
+                        "Python syntax. Remember especially to put quotes around all "
+                        "strings inside lists and dicts.|n For more advanced uses, embed "
+                        "inlinefuncs in the strings."
+                    )
+                else:
+                    string = "Expected {}, got {}.".format(expect, type(prototype))
+                self.caller.msg(string)
+                return
+
+        if expect == dict:
+            # an actual prototype. We need to make sure it's safe,
+            # so don't allow exec.
+            # TODO: Exec support is deprecated. Remove completely for 1.0.
+            if "exec" in prototype and not self.caller.check_permstring("Developer"):
+                self.caller.msg(
+                    "Spawn aborted: You are not allowed to " "use the 'exec' prototype key."
+                )
+                return
+            try:
+                # we homogenize the protoype first, to be more lenient with free-form
+                protlib.validate_prototype(protlib.homogenize_prototype(prototype))
+            except RuntimeError as err:
+                self.caller.msg(str(err))
+                return
+        return prototype
+
+    def _get_prototype_detail(self, query=None, prototypes=None):
+        """
+        Display the detailed specs of one or more prototypes.
+
+        Args:
+            query (str, optional): If this is given and `prototypes` is not, search for
+                the prototype(s) by this query. This may be a partial query which
+                may lead to multiple matches, all being displayed.
+            prototypes (list, optional): If given, ignore `query` and only show these
+                prototype-details.
+        Returns:
+            display (str, None): A formatted string of one or more prototype details.
+                If None, the caller was already informed of the error.
+
+
+        """
+        if not prototypes:
+            # we need to query. Note that if query is None, all prototypes will
+            # be returned.
+            prototypes = protlib.search_prototype(key=query)
+        if prototypes:
+            return "\n".join(protlib.prototype_to_str(prot) for prot in prototypes)
+        elif query:
+            self.caller.msg(f"No prototype found to match the query '{query}'.")
+        else:
+            self.caller.msg(f"No prototypes found.")
+
+    def _list_prototypes(self, key=None, tags=None):
+        """Display prototypes as a list, optionally limited by key/tags. """
+        EvMore(
+            self.caller,
+            str(protlib.list_prototypes(self.caller, key=key, tags=tags)),
+            exit_on_lastpage=True,
+            justify_kwargs=False,
+        )
+
+    @interactive
+    def _update_existing_objects(self, caller, prototype_key, quiet=False):
+        """
+        Update existing objects (if any) with this prototype-key to the latest
+        prototype version.
+
+        Args:
+            caller (Object): This is necessary for @interactive to work.
+            prototype_key (str): The prototype to update.
+            quiet (bool, optional): If set, don't report to user if no
+                old objects were found to update.
+        Returns:
+            n_updated (int): Number of updated objects.
+
+        """
+        prototype = self._search_prototype(prototype_key)
+        if not prototype:
+            return
+
+        existing_objects = protlib.search_objects_with_prototype(prototype_key)
+        if not existing_objects:
+            if not quiet:
+                caller.msg("No existing objects found with an older version of this prototype.")
+            return
+
+        if existing_objects:
+            n_existing = len(existing_objects)
+            slow = " (note that this may be slow)" if n_existing > 10 else ""
+            string = (
+                f"There are {n_existing} existing object(s) with an older version "
+                f"of prototype '{prototype_key}'. Should it be re-applied to them{slow}? [Y]/N"
+            )
+            answer = yield (string)
+            if answer.lower() in ["n", "no"]:
+                caller.msg(
+                    "|rNo update was done of existing objects. "
+                    "Use spawn/update <key> to apply later as needed.|n"
+                )
+                return
+            n_updated = spawner.batch_update_objects_with_prototype(
+                prototype, objects=existing_objects)
+            caller.msg(f"{n_updated} objects were updated.")
+        return
+
+    def _parse_key_desc_tags(self, argstring, desc=True):
+        """
+        Parse ;-separated input list.
+        """
+        key, desc, tags = "", "", []
+        if ";" in self.args:
+            parts = (part.strip().lower() for part in self.args.split(";"))
+            if len(parts) > 1 and desc:
+                key = parts[0]
+                desc = parts[1]
+                tags = parts[2:]
+            else:
+                key = parts[0]
+                tags = parts[1:]
+        else:
+            key = argstring.strip().lower()
+        return key, desc, tags
+
     def func(self):
         """Implements the spawner"""
 
-        def _parse_prototype(inp, expect=dict):
-            err = None
-            try:
-                prototype = _LITERAL_EVAL(inp)
-            except (SyntaxError, ValueError) as err:
-                # treat as string
-                prototype = utils.to_str(inp)
-            finally:
-                if not isinstance(prototype, expect):
-                    if err:
-                        string = (
-                            "{}\n|RCritical Python syntax error in argument. Only primitive "
-                            "Python structures are allowed. \nYou also need to use correct "
-                            "Python syntax. Remember especially to put quotes around all "
-                            "strings inside lists and dicts.|n For more advanced uses, embed "
-                            "inline functions in the strings.".format(err)
-                        )
-                    else:
-                        string = "Expected {}, got {}.".format(expect, type(prototype))
-                    self.caller.msg(string)
-                    return None
-            if expect == dict:
-                # an actual prototype. We need to make sure it's safe. Don't allow exec
-                if "exec" in prototype and not self.caller.check_permstring("Developer"):
-                    self.caller.msg(
-                        "Spawn aborted: You are not allowed to " "use the 'exec' prototype key."
-                    )
-                    return None
-                try:
-                    # we homogenize first, to be more lenient
-                    protlib.validate_prototype(protlib.homogenize_prototype(prototype))
-                except RuntimeError as err:
-                    self.caller.msg(str(err))
-                    return
-            return prototype
-
-        def _search_show_prototype(query, prototypes=None):
-            # prototype detail
-            if not prototypes:
-                prototypes = protlib.search_prototype(key=query)
-            if prototypes:
-                return "\n".join(protlib.prototype_to_str(prot) for prot in prototypes)
-            else:
-                return False
-
         caller = self.caller
+        noloc = "noloc" in self.switches
 
+        # run the menu/olc
         if (
             self.cmdstring == "olc"
             or "menu" in self.switches
@@ -3368,63 +3518,42 @@ class CmdSpawn(COMMAND_DEFAULT_CLASS):
             # OLC menu mode
             prototype = None
             if self.lhs:
-                key = self.lhs
-                prototype = protlib.search_prototype(key=key)
-                if len(prototype) > 1:
-                    caller.msg(
-                        "More than one match for {}:\n{}".format(
-                            key, "\n".join(proto.get("prototype_key", "") for proto in prototype)
-                        )
-                    )
-                    return
-                elif prototype:
-                    # one match
-                    prototype = prototype[0]
-                else:
-                    # no match
-                    caller.msg("No prototype '{}' was found.".format(key))
+                prototype_key = self.lhs
+                prototype = self._search_prototype(prototype_key)
+                if not prototype:
                     return
             olc_menus.start_olc(caller, session=self.session, prototype=prototype)
             return
 
         if "search" in self.switches:
-            # query for a key match
+            # query for a key match. The arg is a search query or nothing.
+
             if not self.args:
-                self.switches.append("list")
-            else:
-                key, tags = self.args.strip(), None
-                if ";" in self.args:
-                    key, tags = (part.strip().lower() for part in self.args.split(";", 1))
-                    tags = [tag.strip() for tag in tags.split(",")] if tags else None
-                EvMore(
-                    caller,
-                    str(protlib.list_prototypes(caller, key=key, tags=tags)),
-                    exit_on_lastpage=True,
-                )
+                # an empty search returns the full list
+                self._list_prototypes()
                 return
 
+            # search for key;tag combinations
+            key, _, tags =  self._parse_key_desc_tags(self.args, desc=False)
+            self._list_prototypes(key, tags)
+            return
+
         if "show" in self.switches or "examine" in self.switches:
-            # the argument is a key in this case (may be a partial key)
+            # show a specific prot detail. The argument is a search query or empty.
             if not self.args:
-                self.switches.append("list")
-            else:
-                matchstring = _search_show_prototype(self.args)
-                if matchstring:
-                    caller.msg(matchstring)
-                else:
-                    caller.msg("No prototype '{}' was found.".format(self.args))
+                # we don't show the list of all details, that's too spammy.
+                caller.msg("You need to specify a prototype-key to show.")
                 return
 
-        if "list" in self.switches:
-            # for list, all optional arguments are tags
-            # import pudb; pudb.set_trace()
+            detail_string = self._get_prototype_detail(self.args)
+            if not detail_string:
+                return
+            caller.msg(detail_string)
+            return
 
-            EvMore(
-                caller,
-                str(protlib.list_prototypes(caller, tags=self.lhslist)),
-                exit_on_lastpage=True,
-                justify_kwargs=False,
-            )
+        if "list" in self.switches:
+            # for list, all optional arguments are tags.
+            self._list_prototypes(tags=self.lhslist)
             return
 
         if "save" in self.switches:
@@ -3435,27 +3564,41 @@ class CmdSpawn(COMMAND_DEFAULT_CLASS):
                 )
                 return
 
+            prototype_key, prototype_desc, prototype_tags = self._parse_key_desc_tags(self.lhs)
+
             # handle rhs:
-            prototype = _parse_prototype(self.lhs.strip())
+            prototype = self._parse_prototype(self.rhs.strip())
             if not prototype:
                 return
 
-            # present prototype to save
-            new_matchstring = _search_show_prototype("", prototypes=[prototype])
-            string = "|yCreating new prototype:|n\n{}".format(new_matchstring)
-            question = "\nDo you want to continue saving? [Y]/N"
+            if prototype.get("prototype_key") != prototype_key:
+                caller.msg("(Replacing `prototype_key` in prototype with given key.)")
+                prototype['prototype_key'] = prototype_key
+            if prototype_desc and prototype.get("prototype_desc") != prototype_desc:
+                caller.msg("(Replacing `prototype_desc` in prototype with given desc.)")
+                prototype['prototype_desc'] = prototype_desc
+            if prototype_tags and prototype.get("prototype_tags") != prototype_tags:
+                caller.msg("(Replacing `prototype_tags` in prototype with given tag(s))" )
+                prototype['prototype_tags'] = prototype_tags
 
-            prototype_key = prototype.get("prototype_key")
-            if not prototype_key:
-                caller.msg("\n|yTo save a prototype it must have the 'prototype_key' set.")
-                return
+            string = ""
+            # check for existing prototype (exact match)
+            old_prototype = self._search_prototype(prototype_key, quiet=True)
 
-            # check for existing prototype,
-            old_matchstring = _search_show_prototype(prototype_key)
+            print("old_prototype", old_prototype)
+            print("new_prototype", prototype)
+            diff = spawner.prototype_diff(old_prototype, prototype, homogenize=True)
+            print("diff", diff)
+            diffstr = spawner.format_diff(diff)
+            new_prototype_detail = self._get_prototype_detail(prototypes=[prototype])
 
-            if old_matchstring:
-                string += "\n|yExisting saved prototype found:|n\n{}".format(old_matchstring)
-                question = "\n|yDo you want to replace the existing prototype?|n [Y]/N"
+            if old_prototype:
+                string = (f"|yExisting prototype \"{prototype_key}\" found. Change:|n\n{diffstr}\n"
+                          f"|yNew changed prototype:|n\n{new_prototype_detail}")
+                question = "\n|yDo you want to apply the change to the existing prototype?|n [Y]/N"
+            else:
+                string = f"|yCreating new prototype:|n\n{new_prototype_detail}"
+                question = "\nDo you want to continue saving? [Y]/N"
 
             answer = yield (string + question)
             if answer.lower() in ["n", "no"]:
@@ -3474,82 +3617,52 @@ class CmdSpawn(COMMAND_DEFAULT_CLASS):
             caller.msg("|gSaved prototype:|n {}".format(prototype_key))
 
             # check if we want to update existing objects
-            existing_objects = protlib.search_objects_with_prototype(prototype_key)
-            if existing_objects:
-                if "update" not in self.switches:
-                    n_existing = len(existing_objects)
-                    slow = " (note that this may be slow)" if n_existing > 10 else ""
-                    string = (
-                        "There are {} objects already created with an older version "
-                        "of prototype {}. Should it be re-applied to them{}? [Y]/N".format(
-                            n_existing, prototype_key, slow
-                        )
-                    )
-                    answer = yield (string)
-                    if answer.lower() in ["n", "no"]:
-                        caller.msg(
-                            "|rNo update was done of existing objects. "
-                            "Use spawn/update <key> to apply later as needed.|n"
-                        )
-                        return
-                n_updated = spawner.batch_update_objects_with_prototype(existing_objects, key)
-                caller.msg("{} objects were updated.".format(n_updated))
+
+            self._update_existing_objects(self.caller, prototype_key, quiet=True)
             return
 
         if not self.args:
+            # all switches beyond this point gets a common non-arg return
             ncount = len(protlib.search_prototype())
             caller.msg(
                 "Usage: spawn <prototype-key> or {{key: value, ...}}"
-                "\n ({} existing prototypes. Use /list to inspect)".format(ncount)
+                f"\n ({ncount} existing prototypes. Use /list to inspect)"
             )
             return
 
         if "delete" in self.switches:
             # remove db-based prototype
-            matchstring = _search_show_prototype(self.args)
-            if matchstring:
-                string = "|rDeleting prototype:|n\n{}".format(matchstring)
-                question = "\nDo you want to continue deleting? [Y]/N"
-                answer = yield (string + question)
-                if answer.lower() in ["n", "no"]:
-                    caller.msg("|rDeletion cancelled.|n")
-                    return
-                try:
-                    success = protlib.delete_prototype(self.args)
-                except protlib.PermissionError as err:
-                    caller.msg("|rError deleting:|R {}|n".format(err))
-                caller.msg(
-                    "Deletion {}.".format(
-                        "successful" if success else "failed (does the prototype exist?)"
-                    )
-                )
+            prototype_detail = self._get_prototype_detail(self.args)
+            if not prototype_detail:
                 return
+
+            string = f"|rDeleting prototype:|n\n{prototype_detail}"
+            question = "\nDo you want to continue deleting? [Y]/N"
+            answer = yield (string + question)
+            if answer.lower() in ["n", "no"]:
+                caller.msg("|rDeletion cancelled.|n")
+                return
+
+            try:
+                success = protlib.delete_prototype(self.args)
+            except protlib.PermissionError as err:
+                retmsg = f"|rError deleting:|R {err}|n"
             else:
-                caller.msg("Could not find prototype '{}'".format(key))
+                retmsg = ("Deletion successful" if success else
+                          "Deletion failed (does the prototype exist?)")
+            caller.msg(retmsg)
+            return
 
         if "update" in self.switches:
             # update existing prototypes
-            key = self.args.strip().lower()
-            existing_objects = protlib.search_objects_with_prototype(key)
-            if existing_objects:
-                n_existing = len(existing_objects)
-                slow = " (note that this may be slow)" if n_existing > 10 else ""
-                string = (
-                    "There are {} objects already created with an older version "
-                    "of prototype {}. Should it be re-applied to them{}? [Y]/N".format(
-                        n_existing, key, slow
-                    )
-                )
-                answer = yield (string)
-                if answer.lower() in ["n", "no"]:
-                    caller.msg("|rUpdate cancelled.")
-                    return
-                n_updated = spawner.batch_update_objects_with_prototype(existing_objects, key)
-                caller.msg("{} objects were updated.".format(n_updated))
+            prototype_key = self.args.strip().lower()
+            self._update_existing_objects(self.caller, prototype_key)
+            return
 
-        # A direct creation of an object from a given prototype
+        # If we get to this point, we use not switches but are trying a
+        # direct creation of an object from a given prototype or -key
 
-        prototype = _parse_prototype(
+        prototype = self._parse_prototype(
             self.args, expect=dict if self.args.strip().startswith("{") else str
         )
         if not prototype:
@@ -3559,35 +3672,20 @@ class CmdSpawn(COMMAND_DEFAULT_CLASS):
         key = "<unnamed>"
         if isinstance(prototype, str):
             # A prototype key we are looking to apply
-            key = prototype
-            prototypes = protlib.search_prototype(prototype)
-            nprots = len(prototypes)
-            if not prototypes:
-                caller.msg("No prototype named '%s'." % prototype)
-                return
-            elif nprots > 1:
-                caller.msg(
-                    "Found {} prototypes matching '{}':\n  {}".format(
-                        nprots,
-                        prototype,
-                        ", ".join(proto.get("prototype_key", "") for proto in prototypes),
-                    )
-                )
-                return
-            # we have a prototype, check access
-            prototype = prototypes[0]
-            if not caller.locks.check_lockstring(
-                caller, prototype.get("prototype_locks", ""), access_type="spawn", default=True
-            ):
-                caller.msg("You don't have access to use this prototype.")
-                return
+            prototype_key = prototype
+            prototype = self._search_prototype(prototype_key)
 
-        if "noloc" not in self.switches and "location" not in prototype:
-            prototype["location"] = self.caller.location
+            if not prototype:
+                return
 
         # proceed to spawning
         try:
             for obj in spawner.spawn(prototype):
                 self.caller.msg("Spawned %s." % obj.get_display_name(self.caller))
+                if not noloc and "location" not in prototype:
+                    # we don't hardcode the location in the prototype (unless the user
+                    # did so manually) - that would lead to it having to be 'removed' every
+                    # time we try to update objects with this prototype in the future.
+                    obj.location = caller.location
         except RuntimeError as err:
             caller.msg(err)

evennia/prototypes/prototypes.py

@@ -56,6 +56,8 @@ _PROTOTYPE_TAG_CATEGORY = "from_prototype"
 _PROTOTYPE_TAG_META_CATEGORY = "db_prototype"
 PROT_FUNCS = {}
 
+_PROTOTYPE_FALLBACK_LOCK = "spawn:all();edit:perm(Admin)"
+
 
 class PermissionError(RuntimeError):
     pass
@@ -84,8 +86,19 @@ def homogenize_prototype(prototype, custom_keys=None):
             homogenizations like adding missing prototype_keys and setting a default typeclass.
 
     """
+    if not prototype or not isinstance(prototype, dict):
+        return {}
+
     reserved = _PROTOTYPE_RESERVED_KEYS + (custom_keys or ())
 
+    # correct cases of setting None for certain values
+    for protkey in prototype:
+        if prototype[protkey] is None:
+            if protkey in ("attrs", "tags", "prototype_tags"):
+                prototype[protkey] = []
+            elif protkey in ("prototype_key", "prototype_desc"):
+                prototype[protkey] = ""
+
     attrs = list(prototype.get("attrs", []))  # break reference
     tags = make_iter(prototype.get("tags", []))
     homogenized_tags = []
@@ -111,12 +124,14 @@ def homogenize_prototype(prototype, custom_keys=None):
 
     # add required missing parts that had defaults before
 
-    if "prototype_key" not in prototype:
+    homogenized["prototype_key"] = homogenized.get("prototype_key",
         # assign a random hash as key
-        homogenized["prototype_key"] = "prototype-{}".format(
-            hashlib.md5(bytes(str(time.time()), "utf-8")).hexdigest()[:7]
-        )
-
+        "prototype-{}".format(
+            hashlib.md5(bytes(str(time.time()), "utf-8")).hexdigest()[:7]))
+    homogenized["prototype_tags"] = homogenized.get("prototype_tags", [])
+    homogenized["prototype_locks"] = homogenized.get(
+        "prototype_lock", _PROTOTYPE_FALLBACK_LOCK)
+    homogenized["prototype_desc"] = homogenized.get("prototype_desc", "")
     if "typeclass" not in prototype and "prototype_parent" not in prototype:
         homogenized["typeclass"] = settings.BASE_OBJECT_TYPECLASS
 
@@ -230,7 +245,7 @@ def save_prototype(prototype):
         "prototype_desc", prototype.get("prototype_desc", "")
     )
     prototype_locks = in_prototype.get(
-        "prototype_locks", prototype.get("prototype_locks", "spawn:all();edit:perm(Admin)")
+        "prototype_locks", prototype.get("prototype_locks", _PROTOTYPE_FALLBACK_LOCK)
     )
     is_valid, err = validate_lockstring(prototype_locks)
     if not is_valid:

evennia/prototypes/spawner.py

@@ -322,9 +322,9 @@ def prototype_from_object(obj):
     return prot
 
 
-def prototype_diff(prototype1, prototype2, maxdepth=2):
+def prototype_diff(prototype1, prototype2, maxdepth=2, homogenize=False):
     """
-    A 'detailed' diff specifies differences down to individual sub-sectiions
+    A 'detailed' diff specifies differences down to individual sub-sections
     of the prototype, like individual attributes, permissions etc. It is used
     by the menu to allow a user to customize what should be kept.
 
@@ -334,6 +334,8 @@ def prototype_diff(prototype1, prototype2, maxdepth=2):
         maxdepth (int, optional): The maximum depth into the diff we go before treating the elements
             of iterables as individual entities to compare. This is important since a single
             attr/tag (for example) are represented by a tuple.
+        homogenize (bool, optional): Auto-homogenize both prototypes for the best comparison.
+            This is most useful for displaying.
 
     Returns:
         diff (dict): A structure detailing how to convert prototype1 to prototype2. All
@@ -350,7 +352,10 @@ def prototype_diff(prototype1, prototype2, maxdepth=2):
         old_type = type(old)
         new_type = type(new)
 
-        if old_type != new_type:
+        if old_type == new_type and not (old and new):
+            # both old and new are unset, like [] or None
+            return (old, new, "KEEP")
+        elif old_type != new_type:
             if old and not new:
                 if depth < maxdepth and old_type == dict:
                     return {key: (part, None, "REMOVE") for key, part in old.items()}
@@ -387,7 +392,10 @@ def prototype_diff(prototype1, prototype2, maxdepth=2):
         else:
             return (old, new, "KEEP")
 
-    diff = _recursive_diff(prototype1, prototype2)
+    prot1 = protlib.homogenize_prototype(prototype1) if homogenize else prototype1
+    prot2 = protlib.homogenize_prototype(prototype2) if homogenize else prototype2
+
+    diff = _recursive_diff(prot1, prot2)
 
     return diff
 
@@ -490,6 +498,80 @@ def prototype_diff_from_object(prototype, obj):
     return diff, obj_prototype
 
 
+def format_diff(diff, minimal=True):
+    """
+    Reformat a diff for presentation. This is a shortened version
+    of the olc _format_diff_text_and_options without the options.
+
+    Args:
+        diff (dict): A diff as produced by `prototype_diff`.
+        minimal (bool, optional): Only show changes (remove KEEPs)
+
+    Returns:
+        texts (str): The formatted text.
+
+    """
+    valid_instructions = ("KEEP", "REMOVE", "ADD", "UPDATE")
+
+    def _visualize(obj, rootname, get_name=False):
+        if is_iter(obj):
+            if not obj:
+                return str(obj)
+            if get_name:
+                return obj[0] if obj[0] else "<unset>"
+            if rootname == "attrs":
+                return "{} |w=|n {} |w(category:|n |n{}|w, locks:|n {}|w)|n".format(*obj)
+            elif rootname == "tags":
+                return "{} |w(category:|n {}|w)|n".format(obj[0], obj[1])
+        return "{}".format(obj)
+
+    def _parse_diffpart(diffpart, rootname):
+        typ = type(diffpart)
+        texts = []
+        if typ == tuple and len(diffpart) == 3 and diffpart[2] in valid_instructions:
+            old, new, instruction = diffpart
+            if instruction == "KEEP":
+                if not minimal:
+                    texts.append("   |gKEEP|n: {old}".format(old=_visualize(old, rootname)))
+            elif instruction == "ADD":
+                texts.append("   |yADD|n: {new}".format(new=_visualize(new, rootname)))
+            elif instruction == "REMOVE" and not new:
+                texts.append("   |rREMOVE|n: {old}".format(old=_visualize(old, rootname)))
+            else:
+                vold = _visualize(old, rootname)
+                vnew = _visualize(new, rootname)
+                vsep = "" if len(vold) < 78 else "\n"
+                vinst = "   |rREMOVE|n" if instruction == "REMOVE" else "|y{}|n".format(instruction)
+                varrow = "|r->|n" if instruction == "REMOVE" else "|y->|n"
+                texts.append(
+                    "   {inst}|W:|n {old} |W{varrow}|n{sep} {new}".format(
+                        inst=vinst, old=vold, varrow=varrow, sep=vsep, new=vnew
+                    )
+                )
+        else:
+            for key in sorted(list(diffpart.keys())):
+                subdiffpart = diffpart[key]
+                text = _parse_diffpart(subdiffpart, rootname)
+                texts.extend(text)
+        return texts
+
+    texts = []
+
+    for root_key in sorted(diff):
+        diffpart = diff[root_key]
+        text = _parse_diffpart(diffpart, root_key)
+        if text or not minimal:
+            heading = "- |w{}:|n\n".format(root_key)
+            if text:
+                text = [heading + text[0]] + text[1:]
+            else:
+                text = [heading]
+
+            texts.extend(text)
+
+    return "\n ".join(line for line in texts if line)
+
+
 def batch_update_objects_with_prototype(prototype, diff=None, objects=None):
     """
     Update existing objects with the latest version of the prototype.
@@ -525,15 +607,13 @@ def batch_update_objects_with_prototype(prototype, diff=None, objects=None):
 
     # make sure the diff is flattened
     diff = flatten_diff(diff)
+
     changed = 0
     for obj in objects:
         do_save = False
 
         old_prot_key = obj.tags.get(category=_PROTOTYPE_TAG_CATEGORY, return_list=True)
         old_prot_key = old_prot_key[0] if old_prot_key else None
-        if prototype_key != old_prot_key:
-            obj.tags.clear(category=_PROTOTYPE_TAG_CATEGORY)
-            obj.tags.add(prototype_key, category=_PROTOTYPE_TAG_CATEGORY)
 
         for key, directive in diff.items():
             if directive in ("UPDATE", "REPLACE"):
@@ -623,6 +703,11 @@ def batch_update_objects_with_prototype(prototype, diff=None, objects=None):
                     pass
                 else:
                     obj.attributes.remove(key)
+
+        # we must always make sure to re-add the prototype tag
+        obj.tags.clear(category=_PROTOTYPE_TAG_CATEGORY)
+        obj.tags.add(prototype_key, category=_PROTOTYPE_TAG_CATEGORY)
+
         if do_save:
             changed += 1
             obj.save()
@@ -707,7 +792,7 @@ def spawn(*prototypes, **kwargs):
     Args:
         prototypes (str or dict): Each argument should either be a
             prototype_key (will be used to find the prototype) or a full prototype
-            dictionary. These will be batched-spawned as one object each. 
+            dictionary. These will be batched-spawned as one object each.
     Kwargs:
         prototype_modules (str or list): A python-path to a prototype
             module, or a list of such paths. These will be used to build

evennia/server/webserver.py

@@ -70,14 +70,15 @@ class HTTPChannelWithXForwardedFor(http.HTTPChannel):
         Check to see if this is a reverse proxied connection.
 
         """
-        CLIENT = 0
-        http.HTTPChannel.allHeadersReceived(self)
-        req = self.requests[-1]
-        client_ip, port = self.transport.client
-        proxy_chain = req.getHeader("X-FORWARDED-FOR")
-        if proxy_chain and client_ip in _UPSTREAM_IPS:
-            forwarded = proxy_chain.split(", ", 1)[CLIENT]
-            self.transport.client = (forwarded, port)
+        if self.requests:
+            CLIENT = 0
+            http.HTTPChannel.allHeadersReceived(self)
+            req = self.requests[-1]
+            client_ip, port = self.transport.client
+            proxy_chain = req.getHeader("X-FORWARDED-FOR")
+            if proxy_chain and client_ip in _UPSTREAM_IPS:
+                forwarded = proxy_chain.split(", ", 1)[CLIENT]
+                self.transport.client = (forwarded, port)
 
 
 # Monkey-patch Twisted to handle X-Forwarded-For.